Here is what The Catholic Encyclopedia reports about it and a related practice:

All Soul’s Day

The commemoration of all the faithful departed is celebrated by the Church on 2 November, or, if this be a Sunday or a solemnity, on 3 November. The Office of the Dead must be recited by the clergy and all the Masses are to be of Requiem, except one of the current feast, where this is of obligation.

The theological basis for the feast is the doctrine that the souls which, on departing from the body, are not perfectly cleansed from venial sins, or have not fully atoned for past transgressions, are debarred from the Beatific Vision, and that the faithful on earth can help them by prayers, almsdeeds and especially by the sacrifice of the Mass. (See PURGATORY.)

In the early days of Christianity the names of the departed brethren were entered in the diptychs. Later, in the sixth century, it was customary in Benedictine monasteries to hold a commemoration of the deceased members at Whitsuntide. In Spain there was such a day on Saturday before Sexagesima or before Pentecost, at the time of St. Isidore (d. 636). In Germany there existed (according to the testimony of Widukind, Abbot of Corvey, c. 980) a time-honoured ceremony of praying to the dead on 1 October. This was accepted and sanctified by the Church. St. Odilo of Cluny (d. 1048) ordered the commemoration of all the faithful departed to be held annually in the monasteries of his congregation. Thence it spread among the other congregations of the Benedictines and among the Carthusians.

Of the dioceses, Liège was the first to adopt it under Bishop Notger (d. 1008). It is then found in the martyrology of St. Protadius of Besançon (1053-66). Bishop Otricus (1120-25) introduced it into Milan for the 15 October. In Spain, Portugal, and Latin America, priests on this day say three Masses. A similar concession for the entire world was asked of Pope Leo XIII. He would not grant the favour but ordered a special Requiem on Sunday, 30 September, 1888.

In the Greek Rite this commemoration is held on the eve of Sexagesima Sunday, or on the eve of Pentecost. The Armenians celebrate the passover of the dead on the day after Easter. (Mershman, Francis. “All Souls’ Day.” The Catholic Encyclopedia. Vol. 1. Nihil Obstat. March 1, 1907. Remy Lafort, S.T.D., Censor. Imprimatur. +John Cardinal Farley, Archbishop of New York. New York: Robert Appleton Company, 1907. 6 Aug. 2013 <http://www.newadvent.org/cathen/01315b.htm>)

A diptych is a sort of notebook…The liturgical use of diptychs offers considerable interest. In the early Christian ages it was customary to write on diptychs the names of those, living or dead, who were considered as members of the Church a signal evidence of the doctrine of the Communion of Saints. Hence the terms “diptychs of the living” and “diptychs of the dead.” Such liturgical diptychs varied in shape and dimension. Their use (sacrae tabulae, matriculae, libri vivorum et mortuorum) is attested in the writings of St. Cyprian (third century) and by the history of St. John Chrysostom (fourth century), nor did they disappear from the churches until the twelfth century in the West and the fourteenth century in the East. (Maere, René. “Diptych.” The Catholic Encyclopedia. Vol. 5. Nihil Obstat. May 1, 1909. Remy Lafort, Censor. Imprimatur. +John M. Farley, Archbishop of New York. New York: Robert Appleton Company, 1909. 6 Aug. 2013 <http://www.newadvent.org/cathen/05022a.htm>)

So, from the above we see that All Souls’ Day is not part of original Christianity and the date has varied. The Roman Catholic practices to it are related to its purgatory doctrine, which is something that did not get developed until many centuries after Jesus–neither purgatory nor All Souls Day were endorsed by the original Church of God (see Did the Early Church Teach Purgatory?). And those in the Continuing Church of God do not endorse it to this day.

Notice another belief associated with All Souls’ Day:

On November 1, All Saints’ Day, adult spirits return, drawn by the ofrendas (altars with offerings), which serve as thresholds between this world and the next…A chair near the altar allows family members to visit with the dead before they depart on November 2nd, when the altar is taken down. The fragile paper decorations, like the transience of flowers, incense, and food, are reminders of the fleeting nature of life. Altars are reminders that the dead are welcomed by the living and continue to have a relationship with us as a natural part of life itself. (Andrade M. The Day of the Dead. http://www.burkemuseum.org/static/RR/DOFD/dofd2.htm. viewed 08/06/13)

Souls are not departing on this day as many falsely believe.

These “festivals of the dead” turn people away from God’s plan of salvation as laid forth by His Holy Days. And these death festivals encourage people to commune with, appease, serve and even worship the dead.

Speaking of the dead, notice also the following:

History of Day of the Dead ~ Día de los Muertos

Day of the Dead is an interesting holiday celebrated in central and southern Mexico during the chilly days of November 1 & 2. Even though this coincides with the Catholic holiday called All Soul’s & All Saint’s Day, the indigenous people have combined this with their own ancient beliefs of honoring their deceased loved ones.

They believe that the gates of heaven are opened at midnight on October 31, and the spirits of all deceased children (angelitos) are allowed to reunite with their families for 24 hours. On November 2, the spirits of the adults come down to enjoy the festivities that are prepared for them. http://www.mexicansugarskull.com/support/dodhistory.html accessed 10/29/16

Of course none of those beliefs about deceased children reuniting for 24 hours are true. But the Church of Rome allows them.

Day of the Dead decorations

Regarding the Day of the Dead, Wikipedia reports:

Day of the Dead (Spanish: Día de Muertos) is a Mexican holiday celebrated throughout Mexico and around the world in other cultures. The holiday focuses on gatherings of family and friends to pray for and remember friends and family members who have died. It is particularly celebrated in Mexico, where it is a national holiday, and all banks are closed. The celebration takes place on November 1 and 2, in connection with the Catholic holidays of All Saints’ Day and All Souls’ Day. Traditions connected with the holiday include building private altars honoring the deceased using sugar skulls, marigolds, and the favorite foods and beverages of the departed and visiting graves with these as gifts. They also leave possessions of the deceased.

Scholars trace the origins of the modern Mexican holiday to indigenous observances dating back hundreds of years and to an Aztec festival dedicated to the goddess Mictecacihuatl. The holiday has spread throughout the world: In Brazil, Dia de Finados is a public holiday that many Brazilians celebrate by visiting cemeteries and churches. In Spain, there are festivals and parades, and, at the end of the day, people gather at cemeteries and pray for their dead loved ones. Similar observances occur elsewhere in Europe, and similarly themed celebrations appear in many Asian and African cultures.

The Day of the Dead is clearly a pagan holiday. Perhaps I should mention that in various places in California, I have seen more and more promotion of the Day of the Dead/Día de Muertos. Its observance seems to becoming more publicly popular in this State.